Heat pump or gas: compare options for your home
Published on 31 July 2026 · Verified on 18 September 2026 · The Mestravaux.lu team
The decision depends on the building, existing heating and renovation plan. Keeping a working boiler is a different comparison from choosing between two new systems. Define the required services first, then request quotations and consumption estimates on the same basis.
The essentials in 30 seconds
- Assess heat loss, emitters and required temperatures before choosing capacity.
- Compare the same heating, hot water provision and usage.
- A point COP does not represent whole-system annual consumption.
- Include related work, maintenance, retained standing charges and future spending.
- Test several price and performance assumptions; no saving is guaranteed here.
Check suitability first
Klima-Agence notes that radiators do not rule out a heat pump. Assess the building, site and occupants’ needs. Check required temperatures, emitter changes, location, noise and electricity supply. Floor area alone is insufficient for selection.
| Poste | PAC air-eau | Chaudière gaz condensation |
|---|---|---|
| Investissement posé | 12 000 – 22 000 € | 6 000 – 9 000 € |
| Aide Klimabonus (indicative) | 20 à 40 % de l'investissement | Non éligible (neuf, fossile) |
| Coût énergie annuel estimé | ≈ 1 000 – 1 200 € | ≈ 1 500 – 1 800 € |
| Entretien annuel | 150 – 350 € | 150 – 250 € |
| Coût énergie cumulé sur 15 ans | ≈ 15 000 – 18 000 € | ≈ 22 500 – 27 000 € |
Chiffres d'exemple pour un scénario type ; à ajuster selon l'isolation réelle du logement, la catégorie de revenu myenergy et l'évolution des prix de l'énergie. Faites établir un bilan thermique et un devis chiffré avant de comparer vos propres scénarios.
Match quotation scope
Compare heating, hot water, removal, circuit changes, electrical work, flue work where relevant and reinstatement. For retained equipment, price the actual work needed. For a heat pump, separate unit, possible backup and adaptations; catalogue price is not installed investment.
Build the energy calculation
For annual useful heat Q, a simplified electricity estimate is Q divided by seasonal system performance; gas is Q divided by seasonal efficiency. Scope must cover the same services and account for backup and auxiliaries without omission or double counting. Multiply by variable tariffs, then add fixed charges separately.
Use an example as arithmetic, not prediction
Purely illustrative calculation: 12,000 kWh useful heat with assumed seasonal performance of 3 gives 4,000 kWh electricity; assumed gas efficiency of 0.90 gives about 13,333 kWh gas. These are neither your building’s figures nor guaranteed performance. Apply dated tariff assumptions, then repeat with different efficiencies.
Your project deserves an accurate estimate — it's free.
Request a quoteInclude maintenance, checks and confirmed grants
Separate maintenance contracts, applicable inspections and repairs. The environment portal distinguishes equipment checks; a maintenance allowance does not prove complete coverage. Assess heat pump support under the applicable Klimabonus criteria instead of a uniform investment percentage.
Compare over a chosen period
Add confirmed net investment and projected spending over the same horizon. State assumed tariff changes, replacements, any residual value and discounting if used. A fifteen-year calculation does not promise fifteen years of equipment life. Show at least one cautious scenario and identify assumptions that easily reverse the result.
Frequently asked questions
Is a heat pump always cheaper to run?
Seasonal performance and tariffs matter, alongside fixed charges and maintenance. Calculate the relevant scenario.
Must all radiators be replaced?
Not automatically. Check their output at proposed temperatures room by room.
Should I wait for the boiler to fail?
There is no universal rule. Assess condition, repairs, continuity of heating and renovation plans.
Can brochure COP be used as annual efficiency?
Not as guaranteed yearly system performance. Request an explained seasonal assumption for your conditions.
Does this comparison predict energy prices?
No. Use several dated scenarios and identify assumptions that change the result.
Take action
Your project deserves an accurate estimate — it's free.
Request a quote